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rtld: allow to use tls_get_addr_slow() from context where rtld_bind_lock is locked

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Explicit locked parameter is added

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D29623
This commit is contained in:
Konstantin Belousov 2021-04-06 21:56:58 +03:00
parent 85d846b369
commit 8950804842
1 changed files with 11 additions and 7 deletions
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18
libexec/rtld-elf/rtld.c
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@ -166,6 +166,7 @@ static int symlook_list(SymLook *, const Objlist *, DoneList *);
static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline;
static void trace_loaded_objects(Obj_Entry *);
static void unlink_object(Obj_Entry *);
static void unload_object(Obj_Entry *, RtldLockState *lockstate);
@ -4871,9 +4872,8 @@ unref_dag(Obj_Entry *root)
/*
* Common code for MD __tls_get_addr().
*/
static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
static void *
tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked)
{
Elf_Addr *newdtv, *dtv;
RtldLockState lockstate;
@ -4882,7 +4882,8 @@ tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
dtv = *dtvp;
/* Check dtv generation in case new modules have arrived */
if (dtv[0] != tls_dtv_generation) {
wlock_acquire(rtld_bind_lock, &lockstate);
if (!locked)
wlock_acquire(rtld_bind_lock, &lockstate);
newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
to_copy = dtv[1];
if (to_copy > tls_max_index)
@ -4891,17 +4892,20 @@ tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
newdtv[0] = tls_dtv_generation;
newdtv[1] = tls_max_index;
free(dtv);
lock_release(rtld_bind_lock, &lockstate);
if (!locked)
lock_release(rtld_bind_lock, &lockstate);
dtv = *dtvp = newdtv;
}
/* Dynamically allocate module TLS if necessary */
if (dtv[index + 1] == 0) {
/* Signal safe, wlock will block out signals. */
wlock_acquire(rtld_bind_lock, &lockstate);
if (!locked)
wlock_acquire(rtld_bind_lock, &lockstate);
if (!dtv[index + 1])
dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
lock_release(rtld_bind_lock, &lockstate);
if (!locked)
lock_release(rtld_bind_lock, &lockstate);
}
return ((void *)(dtv[index + 1] + offset));
}
@ -4916,7 +4920,7 @@ tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
if (__predict_true(dtv[0] == tls_dtv_generation &&
dtv[index + 1] != 0))
return ((void *)(dtv[index + 1] + offset));
return (tls_get_addr_slow(dtvp, index, offset));
return (tls_get_addr_slow(dtvp, index, offset, false));
}
#if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \